The first thing Hitler did to the Jews was take away their firearms. After that it was a piece of cake. All downhill.
And yet the Warsaw Ghetto Uprising was surprisingly effective, with a bare handful of pistols and miscellaneous old weapons of various kinds, many homemade. They managed to hold out against well-armed German troops for an entire month. All that was required was the will. Which the Jews found after news linked that Treblinka was a killing center. Too bad they didn't start a whole lot sooner.